1. Field of the Invention
The present invention relates to an ink cartridge for storing liquid ink for use with an ink jet head or another print head, and supplying the ink to the head. The invention also relates to a printer with which such a cartridge can be used.
2. Description of Related Art
Ink cartridges for use with ink jet printers etc. are classified into a group of cartridges each fixed to a print head, and another group of cartridges each removably fitted to a print head. The removable cartridges each include an ink tank made of resin. The tank houses a foamed or porous member impregnated with ink. The tank has an ink supply port through which ink can be discharged to the head. The tank also has an air vent hole through which air is taken in from the outside when ink is consumed.
For example, U.S. Pat. No. 5,631,682 discloses an ink supply device including a case which houses a foamed or porous member. This member is impregnated with ink and wrapped in a film in bag form. The case has an ink supply port projecting into it and connected to the print head of a printer. When the impregnated and wrapped member is inserted into the case, the projecting port presses the member, piercing the film so that ink is supplied through the port to the head. It is possible to exchange ink by replacing only the impregnated and wrapped member, without throwing away the case, and without the user's hands being smeared with ink.
Recently, a very small portable ink jet printer has been invented as disclosed in Japanese Patent Laid-Open Publications No. 8-295096, No. 8-298568, No. 9-85994 and U.S. Pat. No. 5,634,730. For such a small printer, a cartridge of the foregoing type is not suitable which needs relatively large volume to house in a case a foamed member impregnated with ink. In order that a printer may be portable, it is necessary to completely prevent ink from leaking out of the connection between the print head of the printer and the ink cartridge mounted on the printer, whichever positioned the printer is.